Over the past couple evenings, I’ve completed the second pratice project with no major difficulties. This is a short section of control surface, and incorporates a number of techniques–flush & universal-head riveting, back-riveting, double-flush riveting on the trailing edge, rolling the leading edge, etc. I decided to mix things up and try out a number of different tools/methods for getting things done, in the interest of being more familiar with tha various options. The highlights/things learned:

This should have been obvious (common sense!), but don’t try to save time by not building fixtures to hold things solid during riveting. They even give you a diagram of a fixture, and parts to build it, but it seemed to stand up okay on it’s own, so I gave it a shot…nope. Drilled out 4 rivets I didn’t like. Built the fixture, and life was good. A good lesson.

I have three flush sets–a straight mushroom, a straight mushroom with a rubber ring around the face, and the swivel mushroom that everyone seems to love. So far, I’m preferring the straight set with the rubber ring. Maybe it’s just me, but I had an easier time keeping the gun where I wanted it with that one. I’m curious to try the swivel set again with a two-person rivet/buck operation–I can see where the swivel would be beneficial, and I think it could shine when the shooter is able to hold it against the surface. It tended to walk in the direction of gravity when I was one-handing it.

Duct tape on bucking bars is a goooood thing. I can also see why people are loving the tungsten bucking bars that are the latest rage online; every tool supplier has added them to their catalog. Bucking the skin-spar rivets down in there on the second skin is a challenge with a big bar; I ended up grinding a new face on one of the other bars, since nothing was fitting real well.

Duct tape on squeezer yokes might also be a good thing; I noticed after the fact that I had put a couple scratches in the spar web while dimpling with the pneumatic squeezer, and had to be careful of where I was with the yoke while riveting. I might take a look at deburring those sharp edges? Something to check.

Squeezers: The hand squeezer is easier to control, probably because of its light weight. The pneumatic sets rivets easier! I’m glad for the pneumatic (my hands, I believe, will thank me sooner than later…with some wrist pain from daily activities, I think it’s a wise choice), but I think having the hand squeezer, even the el-cheapo one I have (US Tool) will come in handy in some cases.

My trailing edge came out pretty straight, but I could stand more practice on the double-flush rivets. I didn’t feel like they were setting well. They tended to bend over more than squish down, and some of the results left things a bit loose. I tried a .5 longer rivet in one case, and it may have helped, but still fell over to the side. I may drill these out and re-do for more practice before doing the rudder & elevators.

So that’s it for the practice projects. I had hoped to practice priming and such on this one as well, but haven’t ordered any primer yet. I’ll probably do that on Monday or Tuesday. I need to deburr and dimple the HS skins, and see how people handle the etch step and/or priming only the rivet lines on skins, with the AFS primer. (Looking at web pages, seems like most AFS users are priming the entire inner side of the skins, but inconclusive on the etch step. I wouldn’t think etching the top of the skins would be avoidable, or desired.)

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on Friday, May 25th, 2007 at 10:33 pm and is filed under General.
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Disclaimer: This site follows the construction of an experimental aircraft for my own educational and recreational purposes. The experiences and comments here should not be used as instructions on building any aircraft.